When Mason's Island (now Theodore Roosevelt Island) was purchased in the early 18th-century by the father of George Mason of Gunston Hall, it was then known as Analostan Island. The house (ca. 1796) was built by his grandson, General John Mason (1766-1849), one of the most prominent businessmen in Georgetown. Analostan was never finished, with only the west wing and center hall ever completed.

The interior of the house was destroyed by fire in 1866. The remaining roof and several walls collapsed in a second fire in 1906. Analostan was razed in 1935.